Lesson 7 Flashcards
Transcription and Translation
1
Q
It is the information content of DNA in form of specific sequences of nucleotides along the DNA strands
A
Protein synthesis
2
Q
In protein synthesis, when the DNA is inherited by an organism, it leads to what?
A
specific traits
3
Q
The process by which DNA directs protein synthesis
A
Gene expression
4
Q
The two stages of gene expression
A
Transcription and Translation
5
Q
Simply codes for making polypeptides
A
Genes
6
Q
DNA is stored in:
A
the Nucleus
7
Q
Polypeptide is produced in:
A
the Cytoplasm (by ribosome)
8
Q
A message from the nucleus to the ribosome that is the instructions for how to put the polypeptide together
A
mRNA
9
Q
What do you call the sequence of bases on mRNA
A
Genetic Code
10
Q
This tells the ribosome which amino acids to use
A
Genetic code
11
Q
DNA double helix is unwinding
A
Replication
12
Q
DNA is now single stranded and a new DNA strand forms using what?
A
complementary base pairing
13
Q
Replication is used to prepare DNA for
A
cell division
14
Q
It is when a whole genome is copied/replicated
A
Replication
15
Q
T/F: In a eukaryotic cell, the nuclear envelope separates transcription from translation
A
True
16
Q
In Transcription and Translation, where does extensive RNA processing occur?
A
In the nucleus
17
Q
T/F: The nucleus provides a separate compartment for transcription
A
True
18
Q
The original RNA transcript that is processed in various ways before leaving the nucleus as mRNA
A
pre-mRNA
19
Q
It is the DNA-directed synthesis of RNA
A
Transcription
20
Q
RNA synthesis is catalyzed by ______
A
RNA polymerase
21
Q
It pries the DNA strands apart and hooks together the RNA nucleotides during transcription
A
RNA polymerase
22
Q
RNA synthesis follows the same base-pairing rules as DNA except that
A
Uracil substitutes for Thymine
23
Q
Strands in RNA
A
single
24
Q
RNA is short and is
A
Only 1 gene long
25
Sugar used in RNA
Ribose
26
Base used in RNA
Uracil
27
Types of RNA
mRNA
tRNA
rRNA
28
Carries information specifying amino acid sequences of proteins from DNA to ribosomes
mRNA
29
Serves as adapter molecule in protein synthesis; translates mRNA codons into amino acids
tRNA
30
Plays catalytic roles and structural roles in ribosome
rRNA
31
Catalytic role of rRNA
ribozyme
32
Serves as precursor to mRNA, rRNA or tRNA before being processed by splicing or cleavage. Some intron RNA acts as a ribozyme catalyzing its own splicing.
Primary transcript
33
Plays structural and catalytic roles in spliceosomes, the complexes of protein and RNA that splice pre-mRNA
small nuclear RNA (snRNA)
34
Stages that Transcription and Translation follow
1. Initiation
2. Elongation
3. Termination
35
Initiation in Transcription:
Synthesis of an RNA transcript
36
Signal the initiation of RNA synthesis
Promoters
37
How does RNA polymerase synthesize a single strand of RNA against the anti-sense strand
By adding nucleotides to the 3' end of the RNA chain
37
Help eukaryotic RNA polymerase recognize promoter sequences
Transcription factors
38
RNA polymerase synthesizes a single strand of RNA against the DNA template strand
Elongation in Transcription:
39
As RNA polymerase moves along the DNA, it continues to untwist the doubles by:
Exposing about 10 to 20 DNA bases at a time for pairing with RNA nucleotides
40
Newly synthesized RNA molecule is released from the DNA template
Termination in Transcription:
41
They signal termination of transcription indicating completion
Specific sequences in the DNA (Termination signals)
42
What happens when ones of the specific sequences in the DNA is encountered by the polymerase?
The RNA transcript is released from the DNA and the double helix can zip up again
43
What mechanism is done in the termination of transcription?
Intrinsic
44
When most eukaryotic mRNAs aren't ready to be translated into protein directly after being transcribed, what is required?
Post Termination RNA processing
45
Where does the transcription of RNA processing occur?
Nucleus
46
Where does the mRNA move the transcript for translation?
Cytoplasm
47
What does the cell add to protect the RNA from enzymes that would degrade it?
Protective cap to one end and a tail of As to the other end
48
Non-coding regions
Introns
49
They may have specific chromosomal functions or have regulatory purposes
Non-coding regions
50
Areas that also allows for alternative RNA splicing
Introns
51
Two things that an RNA copy of a gene is converted into a messenger RNA
1. Add protective bases to the ends
2. Cut out the introns
52
How does alteration of mRNA ends?
It is modifying each end of a pre-mRNA molecule on the 5' with a cap as 3' gets a poly-A tail (AAA)
53
It is the original transcript from the DNA
pre-mRNA
54
pre-mRNA contains transcripts of both ________
introns and exons
55
What is removed by a process called splicing to produce mRNA?
Introns
56
The discrete structural and functional regions of the modular architecture of a protein
Domains
57
Different exons code for =
Different domains in a protein
58
What makes an mRNA mature?
When introns are spliced.
59
It is the RNA-directed synthesis of polypeptide
Translation
60
Translation involves
1. mRNA
2. rRNA (ribosomes)
3. tRNA
4. Codons (genetic coding)
61
It is encoded as a sequence of non-overlapping base triplets or codons
Genetic information
62
It is the 3 base code for the production of a specific amino acid
Codons
63
How many possible codons are there with 4 bases and 3 positions?
64 possible codons
64
3 of the 64 codons are used as what
STOP signals
65
Where are the STOP signals found?
at the end of every gene and mark the end of the protein
66
How many codons are used as a START signal as the every protein?
One codon
67
Is the genetic code in all living organisms?
Yes, it is universal
68
It can either be translated into an amino acid or serves as a translational start/stop signal
Codon in mRNA
69
UAA
UAG
UGA
STOP
70
This RNA consist a single that is only 80 nucleotides long
tRNA
71
What does a tRNA carry?
Specific amino acid on one end and an anticodon on the other
72
It pairs the proper tRNA molecules with their corresponding amino acids
A special group of enzymes ;>
73
They bring amino acids to the ribosomes
tRNA
74
AUG
START (Methionine)
75
3 dimensional tRNA molecule shape
rough "L" shape
76
They facilitate the specific coupling of tRNA anticodons with mRNA codons during protein syntehsis
Ribosomes
77
How many subunits in the ribosome are constructed of proteins?
2
78
RNA molecules in the ribosomes are?
rRNA
79
What is in the Ribosome?
2 ribosomal units (proteins) and rRNA
80
What stages of the replication is a polypeptide built?
Translation
81
The bringing together of mRNA (w/ code), tRNA (w/ amino acid), and 2 ribosomal subunits
Initiation in Translation:
82
Amino acids are added one by one to the preceding amino acid
Elongation in Translation:
83
Three steps of Elongation in Translation:
1. Codon recognition
2. Peptide bond formation
3. Translocation
84
What step is when the anticodon of an incoming aminoacyl tRNA base-pairs w/ the complementary mRNA codon in the A site as hydrolysis of GTP (guanosine triphosphate) increases the accuracy and efficiency of this step?
Codon recognition
85
What step is when an rRNA molecule of the large subunit catalyzes the formation of a peptide bond between the new amino acid in the A site and the carboxyl end of the growing polypeptide in the P site. This step attaches the polypeptide to the tRNA in the A site.
Peptide bond formation
86
What step is when the ribosome translocates the tRNA in the A site to the P site. the empty tRNA in the P site is moved to the E site, where it is released. The mRNA moves along with its bound tRNAs, translated into the A site.
Translocation
87
What are the sites in the large ribosomal subunit ?
A, P, and E
88
This subunit is responsible for forming peptide bonds between amino acids, creating the growing polypeptide chain.
Large subunit
89
This subunit is responsible for reading the mRNA sequence and ensuring correct base-pairing with tRNA anticodons.
Small subunit
90
This is where the aminoacyl-tRNA (carrying an amino acid) first binds to the ribosome. It ensures that the correct tRNA is matched with the corresponding codon on the mRNA.
A site (Aminoacyl)
91
This is where the tRNA carrying the growing polypeptide chain resides. It’s where the amino acid from the tRNA in the A site is transferred to the polypeptide chain.
P site (Peptidyl)
92
This is where the empty tRNA, after transferring its amino acid to the polypeptide chain, exits the ribosome to be recharged with another amino acid.
E site (Exit)
93
It is the final stage in which the ribosome reaches a stop codon in the mRNA
Termination in Translation
94
What happens when the ribosome reaches a STOP codon?
There is no corresponding tRNA
95
What attaches to the STOP codon that causes the whole complex (mRNA, 2 ribosomal subunits, and the new polypeptide) to fall apart?
Release factor
96
Can the mRNA be translated many times?
Yes, it can, to produce many protein copies
97
How does the release factor cause the whole complex to fall apart?
The release actor hydrolyzes the bond between the tRNA in the P site and the last amino acid of the polypeptide chain.
98
What happens post-translation?
It might be inserted into a membrane or fold spontaneously into their active configuration and spontaneously join with other polypeptides to form the final proteins
99
What other molecules sometimes also attach to the polypeptides that makes them have special purposes for protein function?
Sugars
Lipids
Phosphates
